L16 Datsun 620 Transmission seals

[Fonseca]

Hey guys just dropped my transmission and my Tranny has been leaking for the longest and finally I got to it! 
 

when I pulled the output shaft seal close to the shifter I saw that the housing had a chip? Can anyone confirm that this isn’t normal and even if I did replace the seal would I continue to leak? 
 

Also i don’t know if the leak could be coming from the o ring where the shifter connects. Please need help !! Hopefully this is repairable with the seals 

[]2eDeYe]

Welcome

Those grooves are to get oil to the seal for lubrication around the slip yoke. 
 

A new seal and you should be good to go.

 

Make sure to check the slip yoke for grooves. 

[datzenmike]

What ]2eDeYe said. The rear seal for the F4W63 is 32136-U0100. It was used in just about every Nissan built after '70. Faster to list cars that don't use it.  It's even used in the 300zx and Xrerra. Rub the seal lips with oil or grease so it doesn't star turning dry.

 

Lightly tap it all the way in. Some replacement seals are thinner. This places the seal lips on fresh unused space on the drive shaft spline

[banzai510(hainz)]

get the double lip seals. I seen SKF branded one only have 1 lip.

[datzenmike]

 

Here's the one I use. Is this single or dual Hainz?

[yenpit]

2 hours ago, datzenmike said:

 

Here's the one I use. Is this single or dual Hainz?

 

Looks to be a SINGLE lip seal............its the INNER lip that rides on the d/s yoke.  A double lip seal will have two of that inner lip,maybe 1/8in apart.  A seal specialist can often take the #'s off of a seal like this one & find a double lip seal with same dimensions.  As an example of a seal specialist, here in Denver we have Whisler Bearing & Rocket Seal.  Bearings & seals go hand in hand..............

[]2eDeYe]

Applied Industrial is the place around here 🙂

[banzai510(hainz)]

the SKF one I had only 1 lip and was made in Mexico.

[Fonseca]

@datzenmike I replaced output and input shaft seals, rear main seal, replaced all 3 gaskets on transmisson as well. I just drove it today after assembly and everyhthing is okay but it still leaks! There isnt any visiable leaking coming from a certain area. All i know is that the driveshaft is splattering it and throwing it up towards the cover where the shifter goes. 

 

As well as under the driver and passenger under the cab, please help I used all oem seals from nissan, plus i made sure they went in flush not to deep! my last thing would be if its leaking from the drive shaft yolk. I googled leaking drive shaft and a couple people said that sometimes it not the seal but the yoke/pinion yoke 

 

can anyone confirm if a 1973 datsun 620 would could have  a  leak coming from here 

 

https://www.youtube.com/watch?v=2o1IguWww_4

[Crashtd420]

If the yoke shaft is scored it could cause a leak past the seal as it's not a perfect seal. Another place to look is where the drive shaft bolts to the yoke... 

Some of those flanges bolted into the transmission others didn't...

I made a mistake when I did a transmission swap and the flange I used had a big hole where the splines were because it bolted in.. if that's the case you can plug that with an engine freeze plug... 

[datzenmike]

Only the 521 truck has the bolt on spline. The 620 just slides into the transmission.

 

 

I Gently tap the seal all the way in. If only flush it will be riding on the previously exposed part of the spline. It may be dirty or rusty. May even be a good idea to polish the spline. 

 

I did get a seal that was half the width. Should have tried using two, I think they both would have fit.

 

Wash away all traces of oil with brake cleaner and let dry. Do around the speedometer cable as well and the plastic vent. Take for a short drive and then examine for first signs of leakage.

 

When you fill the transmission how do you tell when to stop adding???

 

[datzenmike]

Here's a seal that looks different than the one I posted.... Has dozens of squeegee wiper blades to push oil back into transmission

 

 

 

 

[Crashtd420]

13 minutes ago, datzenmike said:

Only the 521 truck has the bolt on spline. The 620 just slides into the transmission.

 

 

I wasnt sure because this is still a 63 series transmission like the 521...

But looking back at the first picture confirmed what you said....

[datzenmike]

The only other vehicle that used this output flange was the 2 liter Roadster.

 

Somewhere around '72? the F4W63 became the F4W63L (I believe it was 63 to 63L not the other way) Outwardly they look identical. Haven't compared internal parts, I expect some upgrades. The F4W63L was used through '79 on the HL510 and '80 on the Canadian HL510 in L series form and had a 'closer' ratio gear set on the Z20 engines. 

 

The 521 and the 510 wagons had the same F4W63 'wider' ratio gears and were identical other than the flange output on the 521. The '72? and up F4W63L only used the 'wider' ratios with the truck transmission. The 610, 710 and HL510 used the same 'mid' ratio transmission for sedans and wagons.

[Fonseca]

16 hours ago, datzenmike said:

Only the 521 truck has the bolt on spline. The 620 just slides into the transmission.

 

 

I Gently tap the seal all the way in. If only flush it will be riding on the previously exposed part of the spline. It may be dirty or rusty. May even be a good idea to polish the spline. 

 

I did get a seal that was half the width. Should have tried using two, I think they both would have fit.

 

Wash away all traces of oil with brake cleaner and let dry. Do around the speedometer cable as well and the plastic vent. Take for a short drive and then examine for first signs of leakage.

 

When you fill the transmission how do you tell when to stop adding???

 

Okay well i don't want to drop the transmission again 😞, @datzenmike where the seal sits did have a couple of minor groves, could this be the reason for leaking? the seal sits exactly how you have yours in the picture i was afraid if i pushed further in that it would cause a leak. I have a couple videos and picture where I think it could be possibly leaking? All i know is that the support/ cross member that is directly under the driveshaft that spins has transmission oil when running my hand above. 

 

i

[Fonseca]

The leak From i would assume is coming from ( click on link to see diagram)!! the drive shaft Yoke. on the image if you look at the beginning where the two u joints come together, underneath that is a big cross member/ bracket with transmission oil on it? 

 

https://www.carpartsmanual.com/datsun/pickup-1972-1979/power-train/propeller-shaft#PhotoSwipe1671259708094

sorry hope this makes sense hard to explain when idk how to post pictures on here from my phone!

 

[datzenmike]

23 hours ago, datzenmike said:

When you fill the transmission how do you tell when to stop adding???

 

 

Could you be over filling the transmission? Oil can be pushed around by wind under the car. Generally pushing it to the rear and down.

 

1/ The plastic vent on top will leak if the transmission is over filled causing the oil to foam.

2/ the speedometer cable can leak.

 

These are the two entry points on the transmission.